In the design of integrated circuit systems, square wave signals are propagated throughout the systems to communicate information and trigger events in a variety of contexts. In the case of clock signals, the same signal may be used throughout a large integrated system. As such, large driver circuits are used to create and to drive the signals throughout the integrated system. Large current changes and voltage changes associated with these signals can create electromagnetic radiation. In certain applications, this electromagnetic radiation can cause electromagnetic interference with other systems. For example, microcontroller systems for automotive applications can cause interference on the radio of the automobile if they emit too much electromagnetic radiation.
The electromagnetic radiation is largely due to the rapid rise and fall times of square wave signals propagated throughout an integrated circuit system. The rapid voltage transitions of a square wave signal when passed into the capacitive network of the integrated circuit can cause high levels of transient current causing interference in associated systems.